(695h) Recent Advances in Evapoporometry for Determining the Pore-Size Distribution of Membranes
EP offers several advantages relative to other methods for determining the PSD. Since the mass can be measured with microgram accuracy, the measurement error in EP is much less than for techniques that require measuring a flow rate, pressure, volume, or heat input. Implementing EP does not require any specialized equipment or expertise. EP also has a relatively small laboratory footprint since the required equipment consists of the test cell, high resolution microbalance, environmental chamber, and an anti-vibration table. Since EP characterization is carried out at the ambient temperature and pressure, it does not alter the morphology of the membrane sample. EP also can be used to determine the PSD of fully hydrated viable biofilms that cannot be done via other PSD characterization methods. A particular advantage of EP is that it can be used to measure the effect of internal pore fouling on the PSD that cannot be done using any method that involves liquid displacement via an inert gas or immiscible liquid.
This presentation will provide an overview of the EP characterization method and discuss recent advances in this technology. The latter include an improved EP test cell design, improving the resolution of EP, extending EP to larger pore sizes, accounting for the effect of the residual adsorbed layer on the pore walls, and adapting EP for characterizing the PSD on both the outer surface and lumen side of hollow fiber membranes.